JP3930665B2 - Fluid pressure cylinder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid pressure cylinder in which a piston rod is locked at a predetermined position.
[0002]
[Prior art]
As a pneumatic cylinder in which the piston is reciprocated by air pressure, for example, as shown in Japanese Utility Model Publication No. 63-53909, the piston rod is mechanically fastened or locked at the position of its stroke end. There is. In this pneumatic cylinder, a locking cylinder is provided on the head cover provided in the cylinder body, and a locking piston provided in a reciprocating manner in the locking cylinder is engaged with an annular groove formed in the piston rod. I try to match.
[0003]
When the locking piston is engaged with the annular groove, the piston rod is locked, and the piston rod can be prevented from moving even if the supply of air pressure is stopped. On the other hand, the piston rod is unlocked by retreating the locking piston by supplying compressed air to the locking cylinder.
[0004]
[Problems to be solved by the invention]
In a pneumatic cylinder having such a lock cylinder, the lock piston is moved forward by the spring force of the coil spring after the lock piston is moved backward by air pressure to release the lock. When the piston rod moves backward, the tip of the locking piston comes into contact with the outer peripheral surface of the piston rod, and scratches are formed on the outer peripheral surface of the piston rod. Further, it is necessary to form a taper portion at the rear end of the piston rod so that when the piston rod moves backward, the locking piston rides up and moves backward.
[0005]
An object of the present invention is to prevent the lock member from coming into contact with the outer peripheral surface of the piston rod under a state where the lock piston releases the lock of the piston rod.
[0006]
[Means for Solving the Problems]
A fluid pressure cylinder according to the present invention is a fluid pressure cylinder in which a piston rod mounted in a cylinder body so as to be reciprocally movable in a linear direction is locked at a predetermined stop position. A locking cylinder in which a member is reciprocally mounted in a radial direction of the piston rod; a meshing portion provided on the piston rod and having an engaging portion with which the locking member engages; A shutter member that is provided on the front end side and is provided in the cylinder body so as to be capable of reciprocating in the axial direction of the piston rod. The shutter member includes a through hole through which the lock member passes and a stopper surface that regulates the front end of the lock member. has the door, the through hole when the piston rod is moved to the stop position is to follow the piston rod corresponding to said locking member The shutter member is moved until the location, wherein said locking member is adapted to lock said piston rod engaged with the engaging portion through the through hole.
[0007]
In the present invention, two cylinders for locking may be provided in the cylinder body so as to correspond to the forward stroke end and the backward stroke end of the piston rod.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
FIG. 1 is a partially omitted sectional view showing a principal part of a fluid pressure cylinder according to an embodiment of the present invention in the unlocked state, and FIG. 2 is a half sectional view showing a principal part of the fluid pressure cylinder in a locked state. 3 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 4 is a view taken along the line BB in FIG.
[0010]
This fluid pressure cylinder has a cylinder tube 11a having a cylinder chamber with a circular cross section inside, and a lock tube 11b attached to this end, and these constitute a cylinder body 11. A head cover 12 is attached to one end portion of the cylinder body 11 by a fixing ring 13, and a rod cover 14 is attached to the other end portion of the cylinder body 11 by a fixing ring 15.
[0011]
A piston 16 is mounted in the cylinder body 11 so as to be capable of reciprocating in the axial direction. A piston rod 17 is attached to the piston 16, and the piston rod 17 passes through a through hole formed in the rod cover 14. Projecting outward from the cylinder body 11.
[0012]
In the cylinder body 11, a forward pneumatic chamber 18a is formed on one side of the piston 16, and a backward pneumatic chamber 18b is formed on the other side of the piston 16. The supply / discharge port 19a communicates with the pneumatic chamber 18a. And a supply / discharge port 19b communicating with the pneumatic chamber 18b are formed in the cylinder body 11, respectively. Therefore, when compressed air is supplied from the supply / discharge port 19a into the pneumatic chamber 18a and the compressed air in the pneumatic chamber 18b is discharged from the supply / discharge port 19b, the piston rod 17 moves forward in a direction protruding from the cylinder body 11. On the other hand, when compressed air is supplied from the supply / discharge port 19b into the pneumatic chamber 18b and the compressed air in the pneumatic chamber 18a is discharged from the supply / discharge port 19a, the piston rod 17 moves backward in the direction of entering the cylinder body 11.
[0013]
The lock tube 11 b is integrally provided with a lock cylinder 21, and a lock piston 23 is mounted in the lock cylinder 21 so as to reciprocate. The lock piston 23 is arranged in the radial direction of the piston rod 17. Reciprocates. The locking piston 23 has a ring shape, and a locking member 24 is integrally provided on the locking piston 23 via a cylindrical portion integrated therewith.
[0014]
A cylinder cover 25 is attached to the lock cylinder 21, and a compression coil spring 26 is provided in the lock cylinder 21 to apply a spring force in the forward direction toward the center of the cylinder body 11 to the lock member 24. Is incorporated. In order to move the lock member 24 backward, a communication passage 27 is provided in the lock cylinder 21 for communicating the air pressure chamber 22 and the air pressure chamber 18 b provided in the lock cylinder 21. Therefore, when the compressed air supplied to the supply / discharge port 19b is supplied into the pneumatic chamber 22 through the communication passage 27, the lock member 24 moves backward against the spring force.
[0015]
The piston rod 17 is provided with an engaging portion 28 integrally with the piston 16, and the engaging portion 28 is formed with an engaging portion 29 with which the lock member 24 is engaged. The engaging portion 29 is positioned in front of the lock member 24 when the piston rod 17 reaches the forward limit position.
[0016]
A cylindrical shutter member 31 is slidably provided in the axial direction outside the meshing portion 28, and a stepped portion 33 that contacts the contact surface 32 on the front side of the meshing portion 28 is provided at the end of the shutter member 31. Is provided. Therefore, when the piston rod 17 moves forward and approaches the forward limit position, the contact surface 32 comes into contact with the stepped portion 33 and follows the forward movement of the piston rod 17 to move the shutter member 31 to the forward limit position.
[0017]
A compression coil spring 34 is provided between the rod cover 14 and the shutter member 31 in order to apply a spring force in a direction in which the shutter member 31 is pressed against the contact surface 32. Therefore, when the piston rod 17 moves backward, the shutter member 31 follows the piston rod 17 by the spring force of the compression coil spring 34 within a predetermined stroke range. In order to restrict the backward movement of the shutter member 31 when the shutter member 31 moves backward by a predetermined stroke, the cylinder body 11 is provided with a stopper surface 35 that contacts the end surface 31a of the shutter member 31.
[0018]
FIG. 1 shows a state in which the end surface 31a of the shutter member 31 is in contact with the stopper surface 35. In this state, the forward movement of the lock member 24 is restricted by the outer peripheral surface of the shutter member 31 serving as the stopper surface. On the other hand, when the piston rod 17 reaches the forward limit position, a through hole 36 is formed in the shutter member 31 in order to engage the lock member 24 with the engaging portion 29 of the meshing portion 28. As shown in FIG. 4, the through hole 36 has a rectangular shape, and the tip of the lock member 24 has a shape that enters the rectangular through hole 36.
[0019]
The locking member 24 has the inclined surface 24a is provided in contact with the inclined surface 29a provided on the engaging portion 29, as shown in FIG. 2, in the state in which both of the inclined surfaces 24a, 29a are in contact, the meshing portion 28 is sandwiched between the rod cover 14 and the lock member 24, and the movement of the piston rod 17 in the forward and backward directions is restricted.
[0020]
In the above-described fluid pressure cylinder, when compressed air is supplied from the supply / discharge port 19a in a state where the piston rod 17 is in the retreat limit position, the piston rod 17 projects in a direction protruding from the cylinder body 11. It will move forward. When the contact surface 32 comes into contact with the step portion 33 of the shutter member 31 along with the forward movement, the shutter member 31 moves forward together with the piston rod 17. Thus, when the piston rod 17 moves to the forward limit position, the through hole 36 becomes the position of the lock member 24, and the lock member 24 penetrates the through hole 36 by the spring force of the compression coil spring 26 and engages 29. Engage with. As a result, the piston rod 17 is locked, that is, fastened by the lock member 24, and the piston rod 17 is held stopped even when a load is applied to the piston rod 17 in the backward movement direction.
[0021]
On the other hand, when the piston rod 17 is moved backward, compressed air is supplied to the supply / discharge port 19b. The compressed air supplied from the supply / discharge port 19b flows into the pneumatic chamber 22 through the communication passage 27, and moves the locking piston 23 backward against the spring force. As a result, the lock member 24 is separated from the engaging portion 29 and the lock of the piston rod 17 is released. Further, the piston rod 17 moves backward by the air pressure flowing into the air pressure chamber 18b from the supply / discharge port 19b.
[0022]
In the illustrated fluid pressure cylinder, the air flowing in from the supply / discharge port 19b is supplied into the pneumatic chamber 22 through the communication passage 27 in order to move the locking piston 23 backward against the spring force. However, compressed air may be supplied directly into the pneumatic chamber 22. Also, the piston rod 17 is locked when the piston rod 17 reaches the forward limit position. However, by changing the position of the locking cylinder 21, the piston rod 17 can be moved at any position of the reciprocating stroke. Can also be locked.
[0023]
In the illustrated fluid pressure cylinder, the piston rod 17 is locked when the piston rod 17 reaches the forward limit position, but may be locked when the piston rod 17 reaches the backward limit position. . In this case, the locking cylinder 21 is provided on the cylinder cover 25 side of the cylinder body 11, and the shutter member 31 is disposed so that both ends are opposite to each other.
[0024]
FIG. 5 is a schematic front view showing a fluid pressure cylinder according to another embodiment of the present invention. In this case, locking cylinders 21 a and 21 b are provided at both ends of the cylinder body 11. Therefore, in this case, the piston rod 17 can be locked at both stroke end positions when the piston rod 17 reaches the forward limit position and when the piston rod 17 reaches the backward limit position. Are provided with two engaging portions, that is, an engaging portion with which the locking member in the locking cylinder 21a is engaged when the forward limit position is reached, and an engaging portion with which the locking member of the locking cylinder 21b is engaged. It will be.
[0025]
It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
[0026]
For example, although the fluid pressure cylinder of the embodiment is operated by air pressure, the present invention can also be applied to a case where liquid such as oil pressure is used as a working medium. Further, although the lock member 24 is moved forward to the engaging portion 29 by a spring force, it may be moved forward by a fluid pressure and moved backward by a spring force. Furthermore, although the illustrated fluid pressure cylinder is a single rod type in which the piston rod 17 projects from one end of the cylinder body 11, it may be a double rod type that projects from both ends.
[0027]
【The invention's effect】
According to the present invention, when the piston rod is locked, the locking member in the locking cylinder is engaged with the engaging portion provided on the piston rod, and when the lock is released, the locking member contacts the stopper surface of the shutter member. Thus, contact between the lock member and the piston rod is avoided. Thereby, even if the spring force in the forward direction, that is, the locking direction is applied to the lock member, it is possible to prevent the piston rod and the outer peripheral surface of the piston from being scratched.
[Brief description of the drawings]
FIG. 1 is a partially omitted cross-sectional view showing a main part of a fluid pressure cylinder according to an embodiment of the present invention in an unlocked state.
FIG. 2 is a half sectional view showing a main part of a fluid pressure cylinder in a locked state.
3 is a cross-sectional view taken along line AA in FIG.
4 is a view taken along the line BB in FIG. 1;
FIG. 5 is a schematic front view showing a fluid pressure cylinder according to another embodiment of the present invention.
[Explanation of symbols]
11 Cylinder body 12 Head cover 14 Rod cover 16 Piston 17 Piston rods 18a and 18b Pneumatic chambers 19a and 19b Supply / exhaust port 21 Lock cylinder 22 Pneumatic chamber 23 Lock piston 24 Lock member 25 Cylinder cover 26 Compression coil spring 27 Communication path 28 Engagement Part 29 Engagement part 31 Shutter member 31a End surface 32 Contact surface 33 Step part 34 Compression coil spring 35 Stopper surface 36 Through hole

Claims (2)

A fluid pressure cylinder configured to lock a piston rod, which is mounted in a cylinder body so as to be reciprocally movable in a linear direction, at a predetermined stop position;
A locking cylinder provided on the cylinder body, wherein a locking member is reciprocally mounted in a radial direction of the piston rod;
A meshing portion provided on the piston rod and formed with an engaging portion with which the locking member engages;
A through hole through which the lock member penetrates and a stopper surface that regulates the tip of the lock member are provided in the cylinder body so as to be reciprocally movable in the axial direction of the piston rod. A shutter member provided,
When the piston rod moves to the stop position, the shutter member moves following the piston rod until the through hole reaches a position corresponding to the lock member, and the lock member moves through the through hole. A fluid pressure cylinder, wherein the piston rod is locked by engaging with a joint.   2. The fluid pressure cylinder according to claim 1, wherein two cylinders for locking are provided in the cylinder body so as to correspond to a forward stroke end and a backward stroke end of the piston rod.

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